Food-preserving can



Jlme'Z.l 19.25 I1,540,466

E. M. LANG, JR., 3D

Fbon Pa'EsERvING cm Filed Aug. 25. 192i 2 l Inval/101'..

' Edward. M Lanj dd A' 6. w. @am

Patented June 2,1925.

UNITED STATES EDWARD M. LANG, JR., 3D, OF PORTLAND, MAINE.

FOODPRF|SERVING CAN;

Application filed August 23, i921. Serial No. 494,667.

To aZZ whom t may concer/IL:

Be it known that I, FiDwlniD M. LANG, J r., 3d, a citizen of the United Stat-es, residing at Portland, in the county of 'hnnberland and State of' Maine, have invented certain new and useful improvements in Food-Pre serving Cans, oi' which the following is a specification.

My invention relates to the food preserving can commonly known as the sanitary can in which the end sealing joints of the can are formed without solder.

In cans of this type, the body of the can is formed as a cylinder with an outwardly turned can sealing flange at each end. Y

The covers are -lf'orlned, considruingv the can as set in a lvertical position., with an upright annular inverted portion fitting into each head of the can body immediately inside the can flange.

The cover also has a sealing flange ,connecting withsaid upright portion and the joint between the cover and the body of the can is formed by rolling or folding the @over flange and the can flange together and press ing them against the side of the can to ',l'orm what term an involute joint.

In this joint, the can flange. turns over and extends down parallel with the sides of the can and the cover flange turns downwardly over the turned-over can flange and thence extends upward between the latter and the can body.

The sealing joint thus entends upward between the upright portion of the cover and the upper end of the can, thence over the turned portio-n of the can flange, thence downwardly and around the lower edge ot the can flange, thence upwardly and around the extreme edge of the cover flange and then `downwardly vbetween the cover flange and the body of the can, to the open air.

In the operation of processing, whenthe cover is expanded or forced upward at its central portion by the expansion of the steam withinthe can, the lower part ofthe vertical annular portion of the cover, is pulled away from its Contact with the can body and the sealing joint above described is opened at its inner end. When the internal pressure is removed and the can is cooled, the end of theV can is forced inward but the open joint having once been formed, the metal does not return to its original position. lt thus happens that air is very likely to find its way into the interior of the can objects by the use of a flexible metallic gasket formed of'sulicient width to extend well down into the can and interposed between the can flange and the cover flange in such a way that it hugs tightly orfis hemmed7 over the outside surfaceof the folded-over can flange and the inside surface of the top of the can body extending well down intov the interior of the can.y

When the joint is thus constructed, the expanding cover pulls the lower part of the Lupright portion of the cover out of position, the metallic gasket hugs the upper end of thev can body and preserves the closeness of the joint atthat point, preventing any tendency to force ogen the sealing joint, when the can is processed.

l have illustrated my invention by means of the accompanyingY drawing` in which I show the ordinary sanitary can illustrating the various steps by which I apply the metallic gasket `and complete the sealing joint and otherwise illustrating the common sealing or involute joint Vand the defect therein which my invention is intended to correct.

Referring to the drawing:

l is a side elevation or" the can with a vertical section through the cover and with the latter raised somewhat above the top of the. can,

Fig. 2 the cover-with the gasket laid in position,

Fig- 3 is the sameY with the cover flange heinmed over to hold the gesl-ret in pla-ce,

Fig. l is a section illustrating the first operation of forming the joint,

Fig. 5 is the same showing the completed joint, l v

Fig. 6 represents the usual involute 'joint and v Fig. 7. represents the joint forced open ,on the inside by the upward expansion of the central portion of the cover. Figs. 8 and `9 show two ways .of doubling inwardly is a section through one side of both the can flange and cover flange. In

lar sanitary or involute joint by which -thcf cover may be sealed to the can and the latter closed, with one way by which the gasket may be manipulated but it is to be understood that there may be numerous methods by 4which the joint may he assembled and finished.

Y Referring tothe drawing, l represents the can body having the outwardly turned can fiange at each end, 3 represents Vthe cover body, 4 is the upright portion of the same which lies immediately within the can flange` 5 is the cover flange, 7 is the metal gasket and 6 is the hemmed over edge of the cover flange for confining the gasket in place.

In Figs. G and '7, I have illustrated the defect in the ordinary involute joint that my invention is designed to overcome.

It will be seen that when the joint is complete, theupright portion of the cover hugs closely the upper edge of the can body just inside of the can'ange and this space between the portion 4 and the can constitutes the inner end of the sealing joint.

`When the center of the cover expands by t-he pressure from within, the upright portion 4 pulls away from the can body and opens up the inner end ofthe sealing joint.

JAccording to the method I am illustrating herein for forming the joint, the circular gasket 7 is first placed beneath the cover flange and the outer' edge of the flange is then hemmed down over the gasket so that the same is held firmly in'place. rIhe can and the gasket may now be handled as a single article preliminary to the canning operation, the gasket remaining securely in place.

IVhen the can is filled andthe cover applied, the involute joint is rolled or formed with the gasket interposed bet-Ween the can flange and the cover flange, the saine as if no gasket was used, the flanges taking the `same relative position as they would take without the gasket. In Fig. 4, as illustrated the first step in the operation of forming the joint where the periphery of the cover flange isturned downwardly and inwardly. F ig. 5 illustrates the completed joint with the metal gasket in place. It will be seen that the gasket after the joint is formed fits over the outside of the can flange. and extends -well down into the can between portion 4 and the upper end of the can. It is thus in position to hug the edge of the can and when the portion 4 pulls away it `will keep the joint tightly closed. j

llhile it is true that papergaskets have been used in thesejoints, they do not'eXtend down inside the can as does curs, and lif they did, they would not perform the func,- tion of hugging the upper edge fof the can thus keeping the joint closed.

rihe `oaskct is preferably made of relatively tnin metal which has a considerable amount of flexibility. It should be well annealed and without spring but should have sufiicient stiffness to hold firmly when once rolled or compressed in place.

The gasket is not necessarily an independent part but it may be made as an outward extension of the can flange or of the cover flange folded back to occupy the place of the gasket as described.

In Fig. 8, I have illustrated a sealing oint where the can flange or an outward eX- tension thereof is folded back upon itself to form the gasket "4' and in Fig. 9, I have shown a construction where the cover flange is folded back upon itself to form the gasket.

In both these instances, the gasket occupies exactly the same position with respect to the can flangeand cover flange as in Fig. except that in one case it is a continuation of the can flange and in the other a continuation of the cover flange, and the effect of the gasket in the matter of preventing the opening of the sealing joint is substantially the same. In the modification shown in Fig.

9 there is a further and different effect besides preventing the upright portion of the cover from moving away from the can body. lf an opening is-formed between the upright portion of the cover and the inner edge of the gasket the joint thus formed between the gasket which forms a portion of the kcover fiange and the adjacent portion of said can flange if traced upwardly and outwardly will be found to terminate in a closed end or loop and not in the open air so that the danger of forming a leaky joint will be greatly reduced. Both the can flange and the cover flange may be doubled back byy being turned upwardly or downwardly. When the cover flange is doubled by turning downwardly it forms the gasket as shown in Fig. y9. Willen turnedy upwardly the eXtra thickness does not actto provide a gasket but it performs a function nearly as import-ant by stiffening and strengthening the joint and aiding to resist the strain from the confined steam tending to force the oint open.' vWhen paper gaskets are used in the ordinary way they are not of much benefit but if the outer vedge of ythe Vpaper gasket is gripped by-thc hemmed over edge of the cover flange as shown in Fig. 3 it is much more eicient and very often used with good effects;

I claim l. A food preservingcan having an outwardly turned flangev at one end and a cover for saidr can havingan upright portion immediately inside of said can body: and having a cover sealing flange connected with said upright portion and a 'relatively rigid 'metal gasket interposed between said can flange and cover flange, the seid Can flange, metal gasket and oover flange being rolled or folded together' to forni an involnte seeling joint said gasket gripping the joint and being Wide enough to extend down into the interior of tlie can between said upright portion and the Side of the een to prevent by its gripping action the opening of the Sealing goint. 2. A food preserving can having en outwardly turned flange at one end and :i Cover for said can having an upright portion inimediately inside of said can body Cmnd having a eover sealing flange connected with said upright portion and zi relatively rigid inet-(il gasket interposedbetween said een flange and cover flange, the said can flange',

metal gasket and cover flange being rolled or folded together to form en involute sealing joint, Said gasket gripping the'oan between said upright portion and the side of the can to ,prevent the opening of the sealing joint7 seid gasket being integral with the cover and forminga continuation of the cover flange.

EDWARD M. LANG, JR., s. 

